Cross-plot engineering system and method

ABSTRACT

In one embodiment, a method includes facilitating a real-time cross-plot display of drilling-performance data for a current well. The real-time cross-plot display includes a plurality of data plots represented on a common graph such that each data plot specifying at least two drilling parameters. Each data plot includes a plurality of data points such that each data point is expressible as Cartesian coordinates in terms of the at least two drilling parameters. The method further includes receiving new channel data for the current well from a wellsite computer system. In addition, the method includes creating, from the new channel data, new data points for the plurality of data plots as the new channel data is received. Moreover, the method includes updating the plurality of data plots with the new data points as the new data points are created.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 16/404,175, filed on May 6, 2019. U.S. patent application Ser.No. 16/404,175 is a continuation of U.S. patent application Ser. No.15/343,535, filed on Nov. 4, 2016. U.S. patent application Ser. No.15/343,535 is a continuation of Ser. No. 14/018,298, filed on Sep. 4,2013. U.S. patent application Ser. No. 14/018,298 is acontinuation-in-part of U.S. patent application Ser. No. 13/919,240,filed on Jun. 17, 2013. U.S. patent application Ser. No. 13/919,240claims priority from U.S. Provisional Application No. 61/660,565, filedon Jun. 15, 2012. U.S. patent application Ser. No. 14/018,298 claimspriority from U.S. Provisional Application No. 61/697,687, filed on Sep.6, 2012. U.S. patent application Ser. No. 16/404,175, U.S. patentapplication Ser. No. 15/343,535, U.S. patent application Ser. No.14/018,298, U.S. patent application Ser. No. 13/919,240, U.S.Provisional Application No. 61/660,565, and U.S. Provisional ApplicationNo. 61/697,687 are hereby incorporated by reference in their entirety.

BACKGROUND Technical Field

The present invention relates generally to drilling analytics and moreparticularly, but not by way of limitation, to systems and methods forenabling real-time drilling-performance analysis.

History of Related Art

Over the years, the world of drilling has become increasingly technical.Drilling professionals constantly search for engineering solutions toachieve profitable production targets efficiently. Thus, the oil-and-gasindustry continues to develop new drilling-engineering techniques tofacilitate the understanding of geological and physical phenomena thatoccur during drilling operations worldwide. However, it is difficult topresent information in a timely and comprehensive manner, for example,to a drilling engineer, so that appropriate decisions can be made.

SUMMARY OF THE INVENTION

In one embodiment, a method includes, on a central computing systemcomprising at least one server computer, facilitating a real-timecross-plot display of drilling-performance data for a current well. Thereal-time cross-plot display includes a plurality of data plotsrepresented on a common graph such that each data plot specifies atleast two drilling parameters. Each data plot comprises a plurality ofdata points such that each data point is expressible as Cartesiancoordinates in terms of the at least two drilling parameters. The methodalso includes the central computing system receiving new channel datafor the current well from a wellsite computer system. In addition, themethod includes the central computing system creating, from the newchannel data, new data points for the plurality of data plots as the newchannel data is received. Furthermore, the method includes the centralcomputing system updating the plurality of data plots with the new datapoints as the new data points are created.

In one embodiment, a system includes at least one server computer. Theat least one server computer is operable to perform a method. The methodincludes facilitating a real-time cross-plot display ofdrilling-performance data for a current well. The real-time cross-plotdisplay comprises a plurality of data plots represented on a commongraph such that each data plot specifying at least two drillingparameters. Each data plot includes a plurality of data points such thateach data point is expressible as Cartesian coordinates in terms of theat least two drilling parameters. The method further includes receivingnew channel data for the current well from a wellsite computer system.In addition, the method includes creating, from the new channel data,new data points for the plurality of data plots as the new channel datais received. Moreover, the method includes updating the plurality ofdata plots with the new data points as the new data points are created.

In one embodiment, a computer-program product includes a computer-usablemedium having computer-readable program code embodied therein. Thecomputer-readable program code is adapted to be executed to implement amethod. The method includes facilitating a real-time cross-plot displayof drilling-performance data for a current well. The real-timecross-plot display comprises a plurality of data plots represented on acommon graph such that each data plot specifying at least two drillingparameters. Each data plot includes a plurality of data points such thateach data point is expressible as Cartesian coordinates in terms of theat least two drilling parameters. The method further includes receivingnew channel data for the current well from a wellsite computer system.In addition, the method includes creating, from the new channel data,new data points for the plurality of data plots as the new channel datais received. Moreover, the method includes updating the plurality ofdata plots with the new data points as the new data points are created.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

FIG. 1 illustrates a system for facilitating real-timedrilling-performance analysis;

FIG. 2 illustrates a process for performing real-time drilling analysis;

FIG. 3 illustrates an example of real-time drilling-performance analysisvia a real-time display;

FIG. 4 illustrates a process for creating a cross plot;

FIG. 5 illustrates a process for updating a real-time cross-plotdisplay; and

FIGS. 6-7 illustrate examples of real-time cross-plot displays.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

In various embodiments, a real-time cross-plot display can integrate aplurality of data plots that depict selected drilling parameters and/ordrilling events for a given well. In certain embodiments, the real-timecross-plot display can be created when drilling operations commence fora given well and be continuously updated from that point forward.

For purposes of this patent application, drilling parameters can includeany type or segmentation of channel data, input data, calculated data,and combinations thereof. For example, the drilling parameters canrelate to depth, date, densities, geological formation, volume loss andgain, casing points, offset well casing points, trajectory analysis(e.g., inclination, azimuth, etc.), fluid properties (plastic viscosity,yield point, etc.), standard pipe pressure (SPP), rate of penetration(ROP), equivalent circulating density (ECD), gallons per minute (GPM),weight on bit (WOB), torque, hook load, and/or the like. In addition,trapping, drag, friction, resistance, and technical comments can beintegrated while drilling advances meter by meter, thereby allowingsimultaneous identification of a drilling technical condition that isdifferent from what is expected (e.g., a drilling event). In a typicalembodiment, drilling-performance cross plots can be shown in real-timeon a real-time display (i.e., a real-time cross-plot display).

In various embodiments, cross-plots can be defined and used as neededfor a given well. In these embodiments, each cross plot can include aselection of drilling parameters and drilling events, a definedpresentation format, and a defined period of time (e.g., from a timewhen drilling begins). The presentation format can specify, for example,how and where the drilling parameters and drilling events aregraphically presented. In addition, in various embodiments, a drillingprofessional such as, for example, a drilling engineer, can create acustom cross-plot by selecting drilling parameters and drilling eventsand specifying a presentation format.

In addition, in various embodiments, real-time drilling-performanceanalytics such as, for example, pore pressure and fracture gradient, canbe facilitated by leveraging historical drilling-performance data fromoffset wells. As one of ordinary skill in the art will appreciate, anoffset well is a pre-existing well that is in close proximity to thecurrent well. For example, an offset well can be located adjacently tothe current well according to spacing rules defined by applicable law.However, it should be appreciated that immediate adjacency need not berequired.

FIG. 1 illustrates a system 100 for facilitating real-timedrilling-performance analysis. The system 100 includes a wellsitecomputer system 102, a central computing system 108, and acommunications network 106. The wellsite computer system 102 includes acollection server 120, a remote-integration server 122, and a networklink 124. The central computing system 108 includes a main server 110, arepository server 112, and a network link 126. It should be appreciatedthat the depicted configurations of the central computing system 108 andthe wellsite computer system 102 are illustrative in nature. The centralcomputing system 108 and the wellsite computer system can each includeany number of physical or virtual server computers and databases. Forexample, in various embodiments, the remote-integration server 122 maybe omitted or have its functionality integrated into the collectionserver 120. Other modifications and rearrangements will be apparent toone of ordinary skill in the art after reviewing inventive principlescontained herein.

In a typical embodiment, the wellsite computer system 102 is located ator near a wellsite for a current well and communicates with the centralcomputing system 108 over the communications network 106. Thecommunications network 106 may include, for example, satellitecommunication between the network link 124 of the wellsite computersystem 102 and the network link 126 of the central computing system 108.Thus, the network link 124 and the network link 126 can be, for example,satellite links. For simplicity of description, communication betweenthe wellsite computer system 102 and the central computing system 108may be described below without specific reference to the network link124, the network link 126, and the communications network 106.

Using, for example, logging while drilling (LWD), the collection server120 receives and/or generates channel data 104 (e.g., in WITSO) via datareceived from sensors that are in use at the wellsite. A given sensor orother source of data is referred to herein as a “channel.” Data from achannel may be referred to as “channel data,” which term is inclusive ofboth raw data and metadata. The raw data includes, for example, measureddata determined by the sensor or source. The measured data can include,for example, resistivity, porosity, permeability, density, and gamma-raydata. The metadata includes information about the raw data such as, forexample, time, depth, identification information for the channel, andthe like. The collection server 120 transmits the channel data 104 tothe remote-integration server 122, which communicates the channel data104 to the central computing system 108 in real-time.

On the central computing system 108, the main server 110 receives thechannel data 104 from the wellsite computer system 102 and converts thechannel data 104 to a common data format. The conversion of channel datato a common data format is described in detail in U.S. patentapplication Ser. No. 13/829,590, which application is herebyincorporated by reference. As shown, the main server 110 has acalculation engine 128 resident thereon. Via the calculation engine 128,the main server 110 generates calculated data in real-time based on thechannel data 104. The calculation engine 128 can be, for example, asoftware application that implements algorithms to generate thecalculated data. Based on gamma-ray and resistivity data and other inputdata described with respect to FIG. 3, the calculated data can include,for example, pore pressure and a fracture gradient.

The calculation engine 128 can also maintain settings that are utilizedfor generating the calculated data. For example, implementation of Eatonand/or Mathews-and-Kelly algorithms may require certain parameters suchas an Eaton exponent, a matrix stress coefficient, and a Poisson ratio.In a typical embodiment, the settings maintained on the main server 110specify values for such parameters. If the value to be used for a givenparameter is not constant across all wells (e.g. varying based ongeography or well-specific data), the settings further specify rules forselecting or calculating the value, as applicable. The settings permitthe calculation engine 128 to acquire necessary parameters without theneed for individual configuration for each well.

The repository server 112 stores and maintains the channel data 104 andany calculated data according to the common data format. Storage andmaintenance of data according to the common data format is described indetail in U.S. patent application Ser. No. 13/829,590, which applicationis incorporated by reference above. In a typical embodiment, therepository server 112 stores channel data from a plurality of wellsitecomputer systems located at a plurality of wellsites in this fashion. Inaddition, the repository server 112 typically maintains historicaldrilling-performance data (e.g., channel data, calculated data, etc.)for offset wells relative to the current well.

The repository server 112 facilitates a real-time display 114 ofdrilling-performance data related to the wellsite. In a typicalembodiment, the real-time display 114 is provided via a network such as,for example, the Internet, via a web interface. The real-time display114 is typically shown and updated in real time on a computing device116 as the channel data 104 is received. For example, in certainembodiments, the real-time display 114 can include gamma-ray andresistivity data for a formation being drilled. An example of theseembodiments will be described with respect to FIGS. 2 and 3. Asdescribed with respect to FIGS. 2 and 3, the real-time display 114 canallow engineering personnel 118 to perform real-time drilling analysisfor the wellsite.

By way of further example, in various embodiments, the real-time display114 can be a real-time cross-plot display. In these embodiments, thereal-time display 114 is operable to show, on a common graph, across-plot that integrates a plurality of data plots. The cross-plotgenerally includes at least one horizontal axis and at least onevertical axis. Each data plot of the cross-plot generally specifies atleast two drilling parameters such that one drilling parameter isassociated with a horizontal axis of the cross-plot and one drillingparameter is associated with a vertical axis of the cross-plot. In thatway, each data plot represents a set of data points that can beexpressed, for example, as Cartesian coordinates in terms of the atleast two drilling parameters.

For example, if a given data plot specifies fluid gain/loss and time asthe at least two drilling parameters, data points of the given data plotcould be expressed as Cartesian coordinates in terms of a fluidgain/loss value and a time (e.g., day, time, hour) at which the fluidgain/loss value was collected. It should be appreciated that thecross-plot can include more than one horizontal axis and/or more thanone vertical axis. In various embodiments, the inclusion of multiplehorizontal axes and/or multiple vertical axes further facilitates thepresentation of disparate drilling-performance data. Examples of areal-time cross-plot display will be described with respect to FIGS.4-7.

For purposes of illustration, examples of equations that can be used tocompute calculated data will now be described. In some embodiments, porepressure (Pp) can be computed using the Eaton method as embodied inEquation 1 below, where S represents stress (i.e. pressure exerted bythe weight of the rocks and contained fluids thereabove in units of,e.g., g/cc), PPN represents normal pore pressure according to ahydrostatic gradient, Ro represents observed resistivity, Rn representsnormal resistivity, and x represents an Eaton exponent.

$\begin{matrix}{{Pp} = {S - {\left( {S - {PPN}} \right)\left( \frac{Ro}{Rn} \right)^{x}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

For purposes of this example, S, PPN, Ro, and Rn are input data forcalculating pore pressure. In particular, S and Ro are examples ofparameters that can be provided by channel data for the current well.The Eaton exponent (x) is an example of a parameter that can beretrieved from settings maintained by the calculation engine 128 ofFIG. 1. In some embodiments, PPN can also be retrieved from settingsmaintained by the calculation engine 128. In a typical embodiment, Rn isobtained using historical drilling-performance data for an offset well.In this fashion, pore pressure for the current well can be calculated inreal-time by retrieving resistivity data for the offset well. A specificexample will be described with respect to FIG. 3.

In various embodiments, a fracture gradient (Fg) can be computed usingthe Eaton method as embodied in Equation 2 below, where Pp and Srepresent pore pressure and stress, respectively, as described above andv represents a Poisson ratio.

$\begin{matrix}{{Fg} = {{Pp} + {\left( {S - {Pp}} \right)\left( \frac{v}{1 - v} \right)}}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

For purposes of the example of Equation 2, stress (S), pore pressure(Pp) and the Poisson ratio (v) are input data for calculating a fracturegradient for a current well. Pp can be computed as described withrespect to Equation 1 above. Stress (S) can also be obtained asdescribed with respect to Equation 1. The Poisson ratio (v) is anexample of an input value that can be retrieved from settings maintainedby the calculation engine 128 as described with respect to FIG. 1.

In various embodiments, a fracture gradient (Fg) can also be computedusing the Matthews and Kelly method as embodied in Equation 3 below,where Pp and S represent pore pressure and stress, respectively, asdescribed above and κ_(i) represents a matrix stress coefficient.

Fg=Pp+(S−Pp)κ_(i)   Equation 3

For purposes of the example of Equation 3, stress(S), pore pressure (P)and the matrix stress coefficient (κ_(i)) are input data for calculatinga fracture gradient for a current well. The pore pressure (Pp) andstress (S) can be obtained as described with respect to Equation 2.κ_(i) is an example of an input value that can be retrieved fromsettings maintained by the calculation engine 128 as described withrespect to FIG. 1.

FIG. 2 illustrates a process 200 for performing real-time drillinganalysis using the system 100 of FIG. 1. At step 202, the wellsitecomputer system 102 collects the channel data 104 in real-time fromsensors via, for example, LWD. The channel data 104 is received in aninitial data format such as, for example, WITSO. From step 202, theprocess 200 proceeds to step 204. At step 204, the wellsite computersystem 102 transmits the channel data 104 to the central computingsystem 108 via the communications network 106. From step 204, theprocess 200 proceeds to step 206. At step 206, the central computingsystem 108 receives the channel data from the wellsite computer system102. From step 206, the process 200 proceeds to step 208.

At step 208, the central computing system 108 converts the channel data104 to a common data format. From step 208, the process 200 proceeds tostep 210. At step 210, the channel data 104 is stored on the centralcomputing system 108 according to the common data format. From step 210,the process 200 proceeds to step 212. At step 212, the calculationengine 128 generates calculated data based on the channel data 104,settings, and other input data described with respect to FIG. 3. Asdescribed above, the calculation engine 128 may be, for example, asoftware application that implements algorithms to generate thecalculated data. From step 212, the process 200 proceeds to step 214.

At step 214, the central computing system 108 stores the calculateddata. For example, the calculated data can be stored on the repositoryserver 112. From step 214, the process 200 proceeds to step 216. At step216, the central computing system 108 updates the real-time display 114to include selected data such as, for example, all or part of thechannel data 104 and all or part of the calculated data. Examples of thereal-time display 114 will be described in greater detail with respectto FIGS. 3-7. From step 216, the process 200 proceeds to step 218. Atstep 218, the process 200 ends.

FIG. 3 illustrates an example of real-time drilling-performance analysisvia a real-time display 314. To facilitate comparative analysis, forexample, by a drilling engineer, the real-time display 314 depictsdrilling-performance data for both a current well 340 and an offset well342 relative to true vertical depth (TVD). In a typical embodiment, theoffset well 342 is pre-selected and associated with the current well 340due to its geographic proximity to the current well 340. In variousembodiments, the pre-selection can be made by drilling personnel such asa drilling engineer and stored by a repository server such as therepository server 112 of FIG. 1.

The drilling-performance data depicted by the real-time display 314 caninclude, inter alia, selected channel data, input data, calculated data,casing-point data, and event data. The selected channel data includes,for example, channel data from a well site that is received at a centralcomputing system, converted to a common data format, and stored asdescribed with respect to FIGS. 1 and 2. The input data is additionaldata that is received, for example, from a drilling engineer or fromother data stored within a repository such as a repository maintained bythe repository server 112 of FIG. 1. The calculated data is data that iscalculated, for example, by a calculation engine such as the calculationengine 128 of FIG. 1. The casing-point data includes information relatedto the placement and size of casing utilized in a given well. The eventdata is data related to certain detected events at a well such as, forexample, a stuck pipe, lost circulation, or a kick (i.e., undesiredinflux of formation fluid into the wellbore).

With respect to the current well 340, the real-time display 314 showsselected channel data, input data, calculated data, and casing-pointdata. In particular, the selected channel data for the current well 340includes gamma-ray data 320(1), resistivity data 324(1), lithography328(1), and fluid density 332(1). The input data for the current well340 includes gamma-ray trend lines 322(1) (also referred to herein asshale lines) and a resistivity-trend line 326(1) (also referred toherein as a normal compaction trend). The calculated data for thecurrent well 340 includes pore pressure 330(1) and fracture gradient334(1). The casing-point data includes one or more casing points 336(1)(which are updated in real time).

With respect to the offset well 342, the real-time display 314 showsselected channel data, input data, calculated data, casing-point data,and event data. It should be appreciated that all such data for theoffset well 342 is generally historical drilling-performance data (asopposed to real-time data for the current well 340). In particular, theselected channel data for the offset well 342 includes gamma-ray data320(2), resistivity data 324(2), lithography 328(2), and fluid density332(2). The input data for the offset well 342 includes gamma-ray trendlines 322(2) (also referred to herein as shale lines) and aresistivity-trend line 326(2) (also referred to herein as a normalcompaction trend). The calculated data for the current well 340 includespore pressure 330(2) and fracture gradient 334(2). The casing-point dataincludes one or more casing points 336(2). The event data for the offsetwell 342 includes one or more drilling events 338.

With respect to the current well 340, acquisition of the input data willnow be described. As mentioned above, the selected channel data for thecurrent well 340 is displayed and refreshed in real-time as such data isreceived by a central computing system such as, for example, the centralcomputing system 108 of FIG. 1. As the selected channel data isreceived, the central computing system 108 gathers the input data, i.e.,the gamma-ray trend lines 322(1) and the resistivity-trend line 326(1).In a typical embodiment, the gamma-ray trend lines 322(1) are traced bydrilling personnel such as, for example, a drilling, geological orgeophysical engineer, who determines points of shale. Shale, as one ofordinary skill in the art will appreciate, generally emit more gammarays than other sedimentary rocks. The gamma-ray trend lines 322(1)generally connect points of shale and represent an average of thegamma-ray data 320(1) between those shale points (i.e. spanning thattrend line). For example, in various embodiments, a drilling engineermay be prompted at configurable points in time to trace the gamma-raytrend lines.

The resistivity-trend line 326(1) is typically acquired automaticallyfrom historical drilling-performance data for the offset well 342. Inthat way, the resistivity-trend line 326(2) (i.e., the normal compactiontrend for the offset well 342) serves as the resistivity-trend line326(1). The resistivity-trend line 326(2) is a normalization of theresistivity data 324 for the offset well 342.

The calculated data for the current well 340 is generated by a centralcomputing system such as, for example, the central computing system 108of FIG. 1, based on the selected channel data and the input data for thecurrent well 340. In a typical embodiment, the calculated data for thecurrent well 340 has defined relationships, established on the centralcomputing system 108 of FIG. 1, with the selected channel data and theinput data. Particularly, the gamma-ray data 320(1), the gamma-ray trendlines 322(1), the resistivity data 324(1), and the resistivity-trendline 326(1) are leveraged by a calculation engine such as, for example,the calculation engine 128, to compute the pore pressure 330(1) and thefracture gradient 334(1) in real time. In that way, published algorithmssuch as those developed by Eaton and Matthews and Kelly may be used inreal time to compute the pore pressure 330(1) and the fracture gradient334(1).

Moreover, the real-time display 314 also enables other types ofreal-time drilling-performance analyses. As one example of real-timedrilling-performance analysis, the real-time display 314 enablesdrilling personnel such as, for example, drilling engineers, to performreal-time geopressure analysis. Drilling engineers are able to comparethe pore pressure 330(1) and the fracture gradient 334(1) for thecurrent well 340 with the pore pressure 330(2) and the fracture gradient334(2) for the offset well. This real-time geopressure analysis allowsdrilling engineers to compare trends and anticipate changes based on theoffset well 342. The geopressure analysis can also be correlated withthe one or more drilling events 338, as described further below.

Further real-time drilling-performance analysis is enabled by the one ormore drilling events 338. Each of the one or more drilling events 338 istypically plotted at a depth at which a defined adverse drilling eventoccurred in the offset well 342. The one or more drilling events 338 caninclude, for example, stuck pipes, lost circulation, kicks, and thelike. As a result of the geographic proximity between the current well340 and the offset well 342, circumstances that led to the one or moredrilling events 338 are often likely to reoccur at similar depths in thecurrent well 340. Therefore, the real-time display 314 allows drillingpersonnel to anticipate and plan for the one or more drilling events338. In a typical embodiment, when the depth of the current well 340 iswithin a preconfigured distance of the depth at which one of the one ormore drilling events 338 occurred (e.g., 500 feet), an alert isgenerated and presented to responsible personnel. The alert can be, forexample, a beep or alarm. Responsive to the alert, the responsiblepersonnel may perform, for example, the real-time geopressure analysisdescribed above so that it can be determined if the pore pressure 330(1)is trending similarly to the pore pressure 330(2). Corrective actionsuch as an adjustment in the fluid density 332(1) may be taken.

As another example of real-time drilling-performance analysis, thereal-time display 314 further enables casing-point prediction. Asdescribed above, the real-time display 314 shows the one or more casingpoints 336(1) for the current well 340 and the one or more casing points336(2) for the offset well 342. Using data from the one or more casingpoints 336(2), drilling personnel are able to predict both size andplacement for future casing points for the current well 340.

A further example of real-time drilling-performance analysis enabled bythe real-time display 314 relates to density analysis. As describedabove, the real-time display 314 displays both the fluid density 332(1)for the current well 340 and the fluid density 332(2) for the offsetwell 342. By reviewing and comparing density trends, drilling personnelsuch as, for example, drilling engineers, are able to determine if thefluid density 332(1) for the current well 340 should be increased,decreased, or maintained.

In a typical embodiment, the real-time display 314 can be customizedbased on the desires of drilling engineers. For example, the selectedchannel data can include more, less, or different channel data thandescribed above. Likewise, the calculated data can have definedrelationships with other channel data and/or input data for purposes ofperforming different calculations in real time.

FIG. 4 illustrates a process 400 for creating a cross plot using thesystem 100 of FIG. 1. At step 402, the central computing system 108receives a selection of one or more wells from a user such as, forexample, a drilling engineer. In a typical embodiment, the selection isof a current well (e.g., a well that is being drilled). From step 402,the process 400 proceeds to step 404.

At step 404, the central computing system 108 receives a selection of aplurality of data plots for the current well from the user. Each dataplot generally specifies at least two drilling parameters such that onedrilling parameter can be associated with a horizontal axis and onedrilling parameter can be associated with a vertical axis. The at leasttwo drilling parameters can correspond, for example, to depth, date,densities, geological formation, volume loss and gain, casing points,calculated data (e.g. pore pressure), input data, etc.

In some cases, a given data plot of the plurality of data plots can be adrilling-event data plot. The drilling-event data plot can correspond toone or more types of drilling events such as, for example, the one ormore drilling events 338 of FIG. 3. The one or more drilling events caninclude, for example, stuck pipes, lost circulation, kicks, and thelike. The at least two drilling parameters of the drilling-event dataplot can include any of the drilling parameters described above.However, the drilling-event data plot will generally only include datapoints when, for example, a specified Boolean condition defining theevent is met (e.g., stuck pipe, lost circulation, kicks, etc.). The oneor more drilling events can be actual events that have been detected vianew channel data for the current well. The one or more drilling eventscan also be historical drilling events for an offset well that areplotted, for example, at a depth at which such event occurred in theoffset well. In that way, the one or more drilling events can facilitatealerting as described with respect to FIG. 3. From step 404, the process400 proceeds to step 406.

At step 406, the central computing system 108 maps each data plot todata sources for the current well. As described above, each of theplurality of data plots generally specifies at least two drillingparameters. The mapping can include specifying which data fields formthe basis for each drilling parameter. The drilling parameters maydirectly correspond to particular fields of channel data, calculateddata, and/or the like. In that way, when, for example, new channel datafor a current well is received, the central computing system 108 can atthat time create new data points for the plurality of data plots. Insome embodiments, the step 406 may be omitted when, for example, alldrilling parameters are pre-mapped to channel data prior to the user'sselection of the plurality of data plots. From step 406, the process 400proceeds to step 408.

At step 408, the central computing system 108 defines a presentationformat for the cross plot. In a typical embodiment, the presentationformat encompasses specification of, for example, measurement units,data precision/scaling of the cross-plot, presentation attributes (e.g.,color, layout, etc.), and/or the like. In various embodiments, thepresentation format can be defined responsive to manual configuration bythe user, technical personnel acting at the instruction of the user,and/or the like. The presentation format can also be defined based onpre-existing templates. It should be appreciated that different ones ofthe plurality of data plots may share a drilling parameter (e.g., time).In such cases, certain ones of the plurality of data plots may share anaxis of the cross-plot. From step 408, the process 400 proceeds to step410.

At step 410, the central computing system 108 populates the plurality ofdata plots with data points for the current well. From step 410, theprocess 400 proceeds to step 412. At step 412, the central computingsystem facilitates a real-time cross-plot display of the cross-plot in afashion similar to that described above with respect to FIG. 2. Thereal-time cross-plot display can be viewed, for example, by a drillingengineer. In various embodiments, the real-time cross-plot display canbe updated with technical comments of a user such as, for example, thedrilling engineer. The technical comments can include drilling analysisof the user, be inserted at an appropriate place on the cross-plot, andbe persistently stored as part of the cross-plot. The technical commentscan then be viewed by whomever accesses the real-time cross-plotdisplay. After step 412, the process 400 ends.

FIG. 5 illustrates a process 500 for updating a real-time cross-plotdisplay using the system 100 of FIG. 1. The real-time cross-plot displayincludes a plurality of data plots and can be created, for example, asdescribed with respect to FIG. 4. The process 500 begins at step 502. Atstep 502, the central computing system 108 creates new data points forthe plurality of data plots. The new data points can be based on channeldata, calculated data, and/or input data as described above. From step502, the process 500 proceeds to step 504. At step 504, the centralcomputing system 108 populates the plurality of data plots with the newdata points. From step 504, the process 500 proceeds to step 506. Atstep 506, the central computing system 108 updates/refreshes thereal-time cross-plot display. After step 506, the process 500 ends.

FIGS. 6-7 illustrate examples of real-time cross-plot displays. Thereal-time cross-plot displays of FIGS. 6-7 can be created as describedwith respect to FIG. 4. In various embodiments, the real-time cross-plotdisplays of FIGS. 6-7 can also be updated in real-time as described withrespect to FIGS. 2 and 5.

Real-time drilling performance analyses such as those described aboveallow drilling personnel such as, for example, drilling, geological, orgeophysical engineers, to reduce non-productive time (NPT). Alerts,recommendations, and real-time displays such as those described aboveallow drilling personnel to perform better analyses more quickly andmore efficiently using, for example, a single systematic slide providedby a real-time cross-plot display. The automation provided by a systemsuch as, for example, the system 100 of FIG. 1, frees drilling personnelfrom manually gathering information necessary to analyze and makedecisions regarding the drilling performance of a well. For example, invarious embodiments, real-time cross-plot displays such as thosedescribed above can allow establishment of historical and comparativesanalysis for different phases along a given well such as: 17½″, 12¼″,8½″, 6½″ and 5″. Therefore, real-time cross-plot displays can betailored to the objective of the well. Thus, technical analyses and riskdetections can be performed in a timely manner and the drilling processcan be optimized.

Although various embodiments of the method and apparatus of the presentinvention have been illustrated in the accompanying Drawings anddescribed in the foregoing Detailed Description, it will be understoodthat the invention is not limited to the embodiments disclosed, but iscapable of numerous rearrangements, modifications and substitutionswithout departing from the spirit of the invention as set forth herein.

What is claimed is:
 1. A method comprising: on a central computingsystem comprising at least one server computer, facilitating a real-timecross-plot display of drilling-performance data for a current well;wherein the real-time cross-plot display comprises a plurality of dataplots represented on a common graph, each data plot specifying at leasttwo drilling parameters; wherein each data plot comprises a plurality ofdata points, each data point expressible as Cartesian coordinates interms of the at least two drilling parameters; the central computingsystem receiving new channel data for the current well from a wellsitecomputer system; the central computing system creating, from the newchannel data, new data points for the plurality of data plots as the newchannel data is received; and the central computing system updating theplurality of data plots with the new data points as the new data pointsare created.
 2. The method of claim 1, wherein, for each of theplurality of data plots, the central computing system maps the at leasttwo drilling parameters to data sources for the current well.
 3. Themethod of claim 1, comprising: responsive to the receiving of the newchannel data: the central computing system retrieving input datacomprising historical drilling-performance data for an offset wellrelative to the current well; and the central computing system computingcalculated data for the current well based on the channel data and theinput data; and wherein, for at least one data plot of the plurality ofdata plots, a drilling parameter of the at least two drilling parameterscomprises the calculated data.
 4. The method of claim 1, wherein thedrilling-performance data comprises casing-point data for the currentwell and an offset well.
 5. The method of claim 1, wherein the pluralityof data plots comprises at least one drilling-event data plot relatingto one or more adverse drilling events.
 6. The method of claim 5,wherein the one or more adverse drilling events are selected from thegroup consisting of: stuck pipe, lost circulation, and kick.
 7. Themethod of claim 5, wherein the one or more adverse drilling events areevents that previously occurred with respect to an offset well relativeto the current well.
 8. The method of claim 7, comprising generating analert when a depth of the current well is within a preconfigureddistance of a depth at which the one or more adverse drilling eventsoccurred.
 9. The method of claim 1, comprising: receiving a technicalcomment from a user; and inserting the technical comment into thereal-time cross-plot display.
 10. A system comprising: at least oneserver computer, wherein the at least one server computer is operable toperform a method comprising: facilitating a real-time cross-plot displayof drilling-performance data for a current well; wherein the real-timecross-plot display comprises a plurality of data plots represented on acommon graph, each data plot specifying at least two drillingparameters; wherein each data plot comprises a plurality of data points,each data point expressible as Cartesian coordinates in terms of the atleast two drilling parameters; receiving new channel data for thecurrent well from a wellsite computer system; creating, from the newchannel data, new data points for the plurality of data plots as the newchannel data is received; and updating the plurality of data plots withthe new data points as the new data points are created.
 11. The systemof claim 10, wherein, for each of the plurality of data plots, the atleast one server computer maps the at least two drilling parameters todata sources for the current well.
 12. The system of claim 10, themethod comprising: responsive to the receiving of the new channel data:retrieving input data comprising historical drilling-performance datafor an offset well relative to the current well; and computingcalculated data for the current well based on the channel data and theinput data; and wherein, for at least one data plot of the plurality ofdata plots, a drilling parameter of the at least two drilling parameterscomprises the calculated data.
 13. The system of claim 10, wherein thedrilling-performance data comprises casing-point data for the currentwell and an offset well.
 14. The method of claim 10, wherein theplurality of data plots comprises at least one drilling-event data plotrelating to one or more adverse drilling events.
 15. The system of claim14, wherein the one or more adverse drilling events are selected fromthe group consisting of: stuck pipe, lost circulation, and kick.
 16. Thesystem of claim 14, wherein the one or more adverse drilling events areevents that previously occurred with respect to an offset well relativeto the current well.
 17. The system of claim 16, the method comprisinggenerating an alert when a depth of the current well is within apreconfigured distance of a depth at which the one or more adversedrilling events occurred.
 18. The system of claim 10, wherein the methodcomprises: receiving a technical comment from a user; and inserting thetechnical comment into the real-time cross-plot display.
 19. Acomputer-program product comprising a computer-usable medium havingcomputer-readable program code embodied therein, the computer-readableprogram code adapted to be executed to implement a method comprising:facilitating a real-time cross-plot display of drilling-performance datafor a current well; wherein the real-time cross-plot display comprises aplurality of data plots represented on a common graph, each data plotspecifying at least two drilling parameters; wherein each data plotcomprises a plurality of data points, each data point expressible asCartesian coordinates in terms of the at least two drilling parameters;receiving new channel data for the current well from a wellsite computersystem; creating, from the new channel data, new data points for theplurality of data plots as the new channel data is received; andupdating the plurality of data plots with the new data points as the newdata points are created.
 20. The computer-program product of claim 19,wherein the method comprises: responsive to the receiving of the newchannel data: retrieving input data comprising historicaldrilling-performance data for an offset well relative to the currentwell; and computing calculated data for the current well based on thechannel data and the input data; and wherein, for at least one data plotof the plurality of data plots, a drilling parameter of the at least twodrilling parameters comprises the calculated data.